As the Eastern Seaboard of the United States bears the brunt of yet another late season snow storm, a growing body of research proves that the record decline in Arctic sea ice has played a "critical role" in the large and southerly snowfalls of recent years.
Satellite images published Monday by the National Snow and Ice Data Center (NSIDC) in Boulder, Colorado, confirm that the ice extent is close to the minimum ever recorded for this time of year.
"The sea ice is going rapidly. It's 80% less than it was just 30 years ago," said Jennifer Francis of the Rutgers Institute of Coastal and Marine Science. "There has been a dramatic loss."
She goes on to explain that the rapid decline in sea ice is what is affecting the jet stream and leading to the extreme weather currently being experienced in the mid-latitudes.
"It allows the cold air from the Arctic to plunge much further south. The pattern can be slow to change because the [southern] wave of the jet stream is getting bigger. It's now at a near record position, so whatever weather you have now is going to stick around."
Adding to her assertion, in a report published earlier this month in the Proceedings in the National Academy of Scientists, researchers confirm that global-warming induced sea ice loss is causing changes in the "winter Northern Hemisphere atmospheric circulation," including the jet stream, which allows cold Arctic air to reach further south and causes "more frequent episodes of blocking patterns that lead to increased cold surges over large parts of northern continents."
Reporting on this phenomenon, the Guardian writes:
The heavy snowfall and freezing temperatures which have marked March 2013 across the northern hemisphere are in stark contrast to March 2012 when many countries experienced their warmest ever springs. The hypothesis that wind patterns are being changed because melting Arctic sea ice has exposed huge swaths of normally frozen ocean to the atmosphere would explain both the extremes of heat and cold.
According to Carbon Brief blog's summation of "Five Reasons Why the Speed of Arctic Sea Ice Loss Matters," scientists are just beginning to understand the effect that enhanced Arctic sea ice melt will have on northern hemisphere climate.
"If the summer ice covers disappears sooner than climate models project," said Francis, "I would expect to see Arctic amplification intensify sooner, and the effects on the large-scale circulation would become more conspicuous."